A campaign for charity Missing People has been launched on interactive posters to promote a new phone number aimed at reconnecting missing people and their families, supported by the Outdoor Media Centre and DOOH firm Grand Visual.

The creative, by BBH, sees a young boy's first call home to his mother, with the film freezing when the woman answers 'hello'. Viewers can call a number to hear the rest of the conversation, while those who don't phone 'will view the film in poignant silence', Grand Visual explains. Admedia sites in leisure and travel locations feature NFC connectivity, allowing the public to hear the exchange by scanning the poster with their smartphones.

"Our brief to BBH was challenging: can you raise awareness of a vital new number for a charity whose work is not well known or understood?" says Martin Houghton-Brown, chief executive, Missing People. "They have managed to create a campaign which communicates in [the] space of 30 seconds, why the charity exists, and who we are here to help."

The campaign promoting the phone number, 116 000, was launched on International Missing Children's Day at Downing Street. It also appears in cinema and MTV adverts and in print media.